This disclosure is directed to a hydraulic system used to propel a vehicle. More particularly, this disclosure is related to a hydraulic system that includes a gerotor motor.
Hydraulic systems that are used to propel a riding lawnmower and other small vehicles include a pump that is connected to a hydraulic motor. The pump delivers pressurized fluid, e.g., oil, to the hydraulic motor. The hydraulic motor converts the energy from the pressurized oil flow from the pump into torque and speed for transferring rotational motion to propel the riding lawnmower. As the hydraulic motor continues to work frictional forces that result from the moving components of the motor can result in high operating temperatures. Cooling the motor can increase the life of the motor as well as increase the operational efficiency.
It is known in hydraulic systems to introduce cooled oil under pressure to drive an output shaft of the hydraulic motor. In one such known hydraulic system, cooled oil is introduced into the motor and more particularly to the gerotor set in a gerotor motor. The oil exits the motor through a case drain of the motor. Hydraulic motors can also be made to include a pressurized central opening, i.e., the hydraulic motor does not include a case drain, which makes this known cooling system unsuitable for this type of motor.